1. Field of the Invention
The invention concerns a roll stand comprising: two or more pairs of roll housings; roll bearing supports (roll attachment pieces) that are slidingly conducted between the housings of the pairs; and cross-arms that connect these housings outside the roll bearing supports, where these cross-arms are movable, together with thread columns linked to the roll housings, in the direction of the longitudinal axis of said thread columns. This motion is effected by means of pressure nuts inserted in the cross arms.
2. Description of the Related Art
Roll stands of this type have become known especially as universal stands. Here, to create a centering adjustment motion of the horizontal roll pair, the cross-arms that are linked with the roll bearing supports of the respective roll pair have pressure nuts that are disposed in the cross-arm in such a fashion that they cannot rotate. The thread columns which have a screw connection with these pressure nuts have contrary threads at their two ends. They are brought through the roll housings of the roll stand, are mounted therein, and are equipped with drives. Due to the contrary threads, a rotary motion of the thread columns here causes a motion of the two cross-arms of the roll stand in the adjustment direction towards the rolling stock, either towards one another or away from one another.
This generic design of a roll stand only permits moving the two cross-arms simultaneously and in dependence on one another. For this reason, it can be used only for special forms of roll stands, such as universal stands. Another important disadvantage is that the roll housings must be dimensioned comparatively heavier, because of the penetration recesses for the thread columns. Also, the mounting of the threaded columns over their length requires considerable technical effort. The penetration recesses for the threaded columns require a major machining effort in the fabrication of the roll housings.
The invention is based on the aim of improving the generic construction type of the roll stand in such a fashion that it can be used for many types of roll stands, including two-high stands, and that the above-mentioned disadvantages are avoided.